Jeremy Corbyn has said abuse of Labour Party MPs and members "flies in the face" of everything he believes and stands for.
A number of MPs have faced abuse from anti-war protesters after splits emerged within Labour over which way the party should vote on airstrikes against so-called Islamic State in Syria.
They have included Walthamstow MP Stella Creasy, who was forced to leave the House of Commons debate on Wednesday after her staff received abusive phone calls.
As the debate continued in Parliament, the Labour leader said there was no place in the party for "bullying of any sort".
He also highlighted the Prime Minister's comments that those who vote against the airstrikes are "terrorist sympathisers", saying David Cameron was thereby taking part in the abuse and "downgrading" the debate.
Ms Creasy tweeted that she was willing to get police involved if she caught anyone hassling her staff.
Diana Johnson MP claimed she received an email warning MPs faced a vote of no confidence if they supported the Government on the airstrikes.
The email she posted on Facebook said: "If the vote of no confidence is carried the MPs can then limp on until their selection at the next General Election when they will be deselected.
"That is the least the Labour Party members will do to try to wash the blood from their hands of the innocent civilians which the bombs will surely kill."
Numerous other MPs have received abuse on social media and reportedly via email, including former British Army Major Dan Jarvis, Liz Kendall and Emma Reynolds.